How Many Square Feet of Countertop? Slabs for L-Shaped Kitchens
A run of counter is its length times its depth: a 12 ft run 25½ inches deep is 25.5 ft². An L-shaped kitchen with runs of 12 and 8 ft has 38.0 ft², and with a 6 × 3 ft island and a 4 inch backsplash the total is 62.7 ft², which is 2 quartz slabs. The countertop calculator does your kitchen.
Countertop area by layout
25½ in deep, no island or backsplash, 20% allowance:
| Runs | Counter area | With allowance | Quartz slabs |
|---|---|---|---|
| 8 ft | 17.0 ft² | 20.4 ft² | 1 |
| 12 ft | 25.5 ft² | 30.6 ft² | 1 |
| 10 + 6 ft | 29.5 ft² | 35.4 ft² | 1 |
| 12 + 8 ft | 38.0 ft² | 45.6 ft² | 1 |
| 16 + 10 ft | 50.7 ft² | 60.9 ft² | 2 |
| 12 + 8 + 6 ft | 46.2 ft² | 55.5 ft² | 2 |
| 16 + 10 + 8 ft | 63.2 ft² | 75.9 ft² | 2 |
Adding an island
To the L-shaped kitchen above (12 + 8 ft) with a 4 inch backsplash:
| Island | Island area | Total | Quartz slabs |
|---|---|---|---|
| 4 × 2 ft | 8.0 ft² | 52.7 ft² | 2 |
| 5 × 3 ft | 15.0 ft² | 59.7 ft² | 2 |
| 6 × 3 ft | 18.0 ft² | 62.7 ft² | 2 |
| 7 × 3.5 ft | 24.5 ft² | 69.2 ft² | 2 |
| 8 × 4 ft | 32.0 ft² | 76.7 ft² | 2 |
How many slabs by material?
For the 12 + 8 ft L with a 6 × 3 ft island and a 4 inch backsplash (63 ft², 75 ft² with the allowance):
| Material | Size | Slabs or sheets |
|---|---|---|
| Quartz slab (126 × 63 in) | 55 ft² | 2 |
| Granite slab (120 × 55 in) | 45.8 ft² | 2 |
| Laminate sheet (12 × 5 ft) | 60 ft² | 2 |
| Plywood or butcher block (4 × 8 ft) | 32 ft² | 3 |
Measuring for counters
- Measure each run along the wall from corner to corner or to the end of the cabinets, and add the overhang at open ends.
- Measure the depth from the wall to the front edge. Base cabinets are 24 inches, and the counter adds 1 to 1½ inches at the front.
- Corners are counted once, so the second run of an L is shorter by the depth.
- Measure the island including its overhang, which is 12 to 15 inches if you will seat people there.
- Decide the backsplash: none, a 4 inch splash, or full height to the upper cabinets.
Before you order
- Visit the stone yard and look at the actual slab. Veining, color and flaws vary from slab to slab.
- Ask the fabricator to template the counters after the cabinets are fixed, and to lay the cuts out on the slab to place the seams.
- Plan the sink and cooktop cutouts, and the edge profile. An undermount sink needs a solid edge.
- Check the cabinets are level, and that they carry the load: stone is about 16 to 17 lb per ft² at 3 cm thick.
Estimates only: the fabricator's layout sets the slab count.
Frequently asked questions
How many square feet is a kitchen countertop?
An L-shaped kitchen with runs of 12 and 8 feet, 25½ inches deep, has about 38 ft² of counter. With a 6 × 3 ft island and a 4 inch backsplash the total is 63 ft².
How do you calculate countertop square footage?
Multiply each run's length by its depth in feet (25½ inches is 2.125 ft), take the corner overlap off the second run, and add the island and the backsplash. A 12 ft run is 25.5 ft².
How many slabs do I need for my countertops?
About 2 quartz slabs for the 63 ft² kitchen, with a 20% allowance. The fabricator's layout decides the real number.
How much does a granite countertop weigh?
About 16 to 17 pounds per square foot for 3 cm stone, so about 1,034 pounds for this kitchen.
What is the standard countertop depth?
Base cabinets are 24 inches deep, and counters are normally 25 to 25½ inches deep, with a 1 to 1½ inch overhang at the front.
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.